Oustanding ResultsWe have microscopically examined ornithophilic bloodsucking Diptera (Culicidae, Simuliidae, Hippoboscidae) for the presence of trypanosomatids in their guts. We dissected 3270 specimens, namely Culex pipiens (n=898), C. modestus (136), Simulium vernum (1455), S. angustipes (221), and Ornithomyia avicularia (524). All insect species have been found infected with trypanosomatids, and the prevalence usually ranged between 4 to 8% but reached 60% in S. vernum. Blackflies and hippoboscids harboured exclusively trypanosomes (both T. cf. avium s.s. ; T.corvi/culicavium group in hippoboscids). Mosquitoes were infected with T. culicavium and T. avium s. l. but also with monoxenous parasites. Only 4% of the isolated parasite strains were monoxenous while the majority were avian trypanosomes, confirming the vectorial status of the studied insects (Svobodová et al., Medical and Veterinary Entomology, accepted).

We examined the role of shared vectors and parasite phylogenetic relationships on the occurrence of haemoparasites in the nesting populations of raptors in two different areas of the Czech Republic. Altogether, 788 nestlings and 258 adult Eurasian sparrowhawks (Accipiter nisus) and 321 nestlings and 86 adult common buzzards (Buteo buteo) were screened. We conclude that phylogenetically unrelated parasites that share the same vectors tend to have similar distributions within the host populations of two different raptor species. (Svobodová et al. 2015).

While studying isolates from birds and vectors, we have found that at least 12 lineages of avian trypanosomes exist, which split into 3 different groups according to the SSU rRNA gene and RAPD analysis. Each group was further subdivided into several lineages, some of them representing already described or putatively distinct species of avian trypanosomes. Only some lineages included isolates from both avian and vector hosts while many consisted only from bird or insect host isolates (Zídková et al. 2012)

We have described a new trypanosome species, T. culicavium, isolated from culicines. Its transmission was achieved using laboratory-bred Culex quinquefasciatus and canaries. Although the occurrence of trypanosomes on the stomodeal valve suggested transmission by bite (Volf et al. 2004), we have demonstrated that it occurs by ingestion. Natural avian host was found among mosquito-eating passerines (Votýpka et al. 2012).

Different height preferences of ornithophilic vectors were demonstrated using CDC traps baited with chickens.Culicine mosquitoes occur at ground while blackflies in canopy level (Černý et al. 2011). This probably influences potential host spectra of transmitted trypanosomes (T. culicavium, T. cf. avium), and is in accordance with respective modes of transmission, namely ingestion by mosquito-eating birds in T. culicavium, and prediuresis into conjunctiva in T. cf. avium from blackflies to raptors.

Ornithophilic insects have been studied in nestboxes. While midges were caught readily, blackflies and mosquitoes were almost absent (Votýpka et al. 2008). Trypanosomes previously reported in nestlings of cavity breeders thus should not belong to T. cf avium, since it is transmitted by blackflies, but rather to T. bennetti, T. culicavium or other species of avian trypanosomes.

By comparing SSU rDNA sequences of raptor and bloodsucking insects isolates, we have confirmed that T. cf. avium is transmitted by blackflies (Votýpka et al. 2002). Infective forms isolated directly from blackflies (Eusimulim spp.) caught in the wild were used to show that transmission occurs by ingestion or prediuresis (Svobodová & Votýpka 2004).

We have isolated several monoxenous kinetoplastids from bloodsucking Diptera. Three new species of monoxenous kinetoplastids were described from biting midges: Herpetomonas ztiplika, H. trimorpha, and Sergeia podlipaevi (Podlipaev et al. 2004, Zídková et al. 2010, Svobodová et al. 2007). Their transmission to laboratory-bred biting midges was possible from sugar.